2009 ClimateGate email: Warmist MacCracken suggests that Phil Jones start working on a "backup" in case Jones' prediction of warming is wrong

In any case, if the sulfate hypothesis is right, then your prediction of warming might end up being wrong. I think we have been too readily explaining the slow changes over past decade as a result of variability--that explanation is wearing thin. I would just suggest, as a backup to your prediction, that you also do some checking on the sulfate issue, just so you might have a quantified explanation in case the prediction is wrong. Otherwise, the Skeptics will be all over us--the world is really cooling, the models are no good, etc. And all this just as the US is about ready to get serious on the issue.

We all, and you all in particular, need to be prepared.

Best, Mike MacCracken [Note that Obama's chief science advisor, John Holdren, is copied on this email]